50 Trans. Acad. Sci. of St. Louis. 



3. Olivanites elegans, T. a. Conrad. Devonian. 

 Nucleocrinus canadensis, H. Montgomery. 

 Nucleocrinus hallii, L. Vanuxem. 

 Elaeacrinus elegans, Shumard. 

 Nucleocrinus veniistus, Miller aud Gurley. 



*4. Olivanites greeni, S. A., Miller and W. F. E. Gurley. 



Devonian. 

 Nucleocrinus greeni, Miller and Gurley. 



*5. Olivanites globosus, Troost. Devonian. 



6. Olivanites lugina, Hall. Devonian. 

 Nucleocrinus lucina. Hall. 



*7. Olivanites meloniformis, W. H. Barris. Devonian. 



Elaeacrinus meloniformis, Barris. 



8. Olivanites obovatus, W. H. Barris. Devonian. 

 Elaeacrinus obovatus, Barris. 



9. Olivanites verneuili, Lyon. Devonian. 



Pentremites verneuili, Troost. 

 Elaeacrinus vernenili, Roemer. 

 Nucleocrinus verneuili, Bather. 



Those marked with an asterisk may have to be placed 

 in another orenus or mav prove to be identical with one or 

 another abeady known species, which facts can only be 

 established when more material for comparison is available. 



2. Family Eleutheroblastidae. 

 1. Genus Eleutheroblastus. 



General form elliptical, truncated at the summit and sub- 

 triangular at the base. Base very irregular, subtriangular at 

 the lower part, and prolonged on one of its sides to a remark- 

 able length. It consists of three pieces, one small rhombic 

 piece and two large pieces prolonged nearly to the middle of 

 the calyx. Fork pieces four, non-symmetrical, each having a 

 lono' sinus in the center for the reception of the ambulacrum. 

 The two middle pieces have a shorter sinus, whereas the two 



